THURSDAY, Jan. 10 (HealthDay News) -- With the United States in the throes of one of the worst flu outbreaks in years, health-care experts say there are ways you can fight back and protect yourself from the virus.

And the best protection is a flu shot -- even now.

"People should ideally get the flu shot at the beginning of the flu season which really starts in October," said Dr. Robert Graham, an internist at Lenox Hill Hospital in New York City. "So the sooner the better. But at the same time, whenever you can get the shot I strongly recommend it. It's the least painful way of combating the flu."

The good news is that this year's vaccine is an excellent match for the strains of influenza now circulating.

The not-so-great news is that the vaccine takes about two weeks to become fully effective in your body. And even people who have been vaccinated can contract the flu virus, though this is uncommon.

The predominant strain so far this year is H3N2, and doctors note that when H3N2 dominates, they tend to see more severe illness among children and the elderly.

For those who haven't yet had a flu shot -- and even for those who have -- there are other simple precautions people can and should take to minimize the chances of contracting what's turning out to be an especially infectious and unpleasant illness.

First and foremost is to wash your hands, said nurse Kristen Lawton, director of the emergency department at Northern Westchester Hospital in Mount Kisco, N.Y.

"If you can't use soap and water, use the hand soap in a pump or the alcohol-based preparation," she said.

Lawton said her emergency room has been seeing about 15 more patients a day with flu-related illness since Christmas, compared to before the holidays.

The next best advice is to avoid touching your face with your hands. "I tell my kids to keep their hands away from the holes in their head," she said. "Don't be touching your eyes, nose or mouth because there are germs on your hands."

Seemingly safe surfaces like kitchen counters, desks, refrigerator door handles and computer keyboards may also harbor the flu virus for hours -- sometimes as long as 48 hours, according to the Mayo Clinic. Make sure these are kept clean, Lawton counseled.

If you have to cough or sneeze, do so into a tissue or into the crook of your elbow -- not into the air where droplets can easily infect people near you.

Droplets from a vigorous cough can travel at 60 mph, Graham said.

If you do start to feel sick, stay home. An adult is contagious one day before symptoms and between five and seven days after becoming sick, Lawton said. Children may pass the virus for longer than seven days, according to the U.S. Centers for Disease Control and Prevention.

The drug Tamiflu can shorten the course of the illness, Lawton said. And it may prevent it in some people, according to the U.S. Food and Drug Administration.

Other than that, your best bet is to rest, drink lots of fluids and take an over-the-counter pain reliever, Lawton added.

People at particular risk for the flu and its complications are pregnant women, those 65 and older and anyone with a chronic illness. The CDC urges these people to get a flu shot, which is available as an injection or nasal spray and in a stronger dose for seniors.

Forty-one states are reporting widespread flu activity. There have been 18 flu-related deaths of children so far and about 2,300 people have been hospitalized since Oct. 1, according to the CDC.

The epidemic is so bad in Boston, where four flu-related deaths have been reported, that Mayor Thomas Menino declared a state of emergency on Wednesday. The city has already recorded 700 confirmed cases of flu, compared with 70 cases for all of last year, according to Boston.com.